This application claims priority to Japanese patent application serial number 2002-067287, the contents of which are incorporated herein by reference.
The present invention relates to intake manifolds that are connected to engines, e.g. internal combustion engines, in order to supply an intake air to the engines.
Intake manifolds are known that are made of resin and have surge tanks that are disposed on the upstream side. Throttle bodies are joined to the surge tanks. The downstream side of the intake manifolds is joined to engines, e.g., internal combustion engines. Because the rigidity of such intake manifolds made of resin is not sufficient to ensure the reduction of vibrations of the throttle bodies, the throttle bodies are supported by the engines via brackets. Japanese Laid-Open Patent Publication No. 10-107867 teaches such a known intake manifold made of resin.
However, even if the throttle body is supported by the engine, it is not possible to effectively reduce vibrations of the throttle body by the support of bracket.
It is accordingly an object of the present invention to teach improved techniques for effectively reducing vibrations of an upstream-side member, e.g., a throttle body, that is joined to an intake manifold.
According to one aspect of the present teachings, intake manifolds are taught that have a joint made of metal, e.g., aluminum, magnesium and stainless steel. The joint may include an upstream-side portion and a downstream-side portion that are joined to each other. The upstream-side portion may be joined to a manifold body on the upstream-side of the manifold body. The downstream-side portion may be joined to the manifold on the downstream-side of the manifold.
Because the manifold body is joined to the metal joint on both upstream and downstream sides, the rigidity of the entire intake manifold may be improved even in case that the manifold body is made of resin or similar material that has a relatively low rigidity.
An upstream-side end of the upstream-side portion of the joint may be joined to an upstream-side member, e.g. a throttle body. A downstream-side end of the downstream-side portion of the joint may be joined to a rigid fixed member, e.g. a cylinder head of an internal combustion engine.
Therefore, vibrations of the upstream-side member may be reliably reduced due to the rigid support of the intake manifold.
According to another aspect of the present teachings, the upstream-side portion and the downstream portion of the joint may be formed integrally with each other. Therefore, the rigidity of the intake manifold may be further improved.
According to another aspect of the present teachings, the joint may be joined to the manifold body via flanges and fasteners, e.g., bolts.
According to another aspect of the present teachings, the joint may be joined to the manifold body via tubular extensions that are fitted with each other. Therefore, the operation for joining the joint to the manifold body can be facilitated.